In a second day of widespread protests, crowds in the biggest city, Yangon, sported red shirts, red flags and red balloons, the colour of Ms Suu Kyi's National League for Democracy Party (NLD). "We don't want military dictatorship! We want democracy!" they chanted.
On Sunday afternoon, the junta ended a day-long blockade of the internet that had further inflamed anger since the coup last Monday that has halted the South East Asian nation's troubled transition to democracy and drawn international outrage. Thousands of riders also took to the streets of south-eastern city of Dawei on their motorcycles to denounce to coup.
Pope Francis expressed "solidarity with the people" on Sunday and asked Myanmar's leaders to seek "democratic" harmony. Massive crowds from all corners of Yangon gathered in townships, filling streets as they headed towards the Sule Pagoda at the heart of the city, also a rallying point during the Buddhist monk-led 2007 protests and others in 1988.
Lines of armed police with riot shields set up barricades, but did not try to stop the demonstration. Some marchers presented police with flowers. One officer was photographed giving a surreptitious three-finger salute.
There was no comment from the junta in the capital Naypyidaw, and state-run television news carried no mention of the protests. An internal note for UN staff estimated that 1,000 people joined a protest in the capital, Naypyidaw, while there were 60,000 in the former capital and largest city, Yangon.
Protests were reported in the second city of Mandalay and many towns and even villages across the country of 53 million people that stretches from Indian Ocean islands to the fringes of the Himalayas. The Yangon protesters dispersed after dark.
The demonstrations have largely been peaceful, unlike the bloody crackdowns seen in 1998 and 2007. But shots were heard in the south-eastern town of Myawaddy as uniformed police with guns charged a group of a couple of hundred protesters, live video showed.
Pictures of protesters afterwards showed what appeared to be rubber bullet injuries. With no internet and official information scarce, rumours swirled about the fate of Ms Suu Kyi and her cabinet. A story that she had been released drew crowds out to celebrate on Saturday, but it was quickly quashed by her lawyer.
Ms Suu Kyi, 75, faces charges of illegally importing six walkie-talkies and is being held in police detention for investigation until February 15. Her lawyer said he has not been allowed to see her.
She won the Nobel Peace Prize in 1991 for campaigning for democracy, and spent nearly 15 years under house arrest during decades of struggling to end almost half a century of army rule before the start of a troubled transition to democracy in 2011.
Army Chief Min Aung Hlaing carried out the coup on the grounds of fraud in a November 8 election that Ms Suu Kyi's party won in a landslide. The electoral commission has dismissed the allegations of malpractice. More than 160 people have been arrested since the military seized power, said Thomas Andrews, the United Nations special rapporteur on Myanmar.
"The generals are now attempting to paralyse the citizen movement of resistance — and keep the outside world in the dark — by cutting virtually all internet access," Mr Andrews said in a statement on Sunday. "We must all stand with the people of Myanmar in their hour of danger and need. They deserve nothing less."